DateAdd function malfunctions?

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  • Rich Raffenetti
    #1

    DateAdd function malfunctions?

    I have the following code. If I do the dateadd function with
    dateinterval.mi nute, it works fine and the date/time value is displayed with
    zero seconds. If I do the dateadd function with dateinterval.se cond, an
    error is thrown saying I have an overflow. I would be happy to know if I am
    doing something wrong or if I could do it differently to get the seconds to
    display properly.

    Const largeInteger As Long = &H1C5EA3B5F585F 1F
    Const dateRef As Date = #1/1/1601#
    TextBox1.Text = CStr(DateAdd(Da teInterval.Minu te, CDbl(largeInteg er
    / (60 * 10000000)), dateRef))
    'TextBox1.Text = CStr(DateAdd(Da teInterval.Seco nd, CDbl(largeInteg er
    / 10000000), dateRef))

    I am doing this in Visual Web Developer Express.


    Tags: None
    • Larry Lard
      #2
      Re: DateAdd function malfunctions?


      Rich Raffenetti wrote:[color=blue]
      > I have the following code. If I do the dateadd function with
      > dateinterval.mi nute, it works fine and the date/time value is displayed with
      > zero seconds. If I do the dateadd function with dateinterval.se cond, an
      > error is thrown saying I have an overflow. I would be happy to know if I am
      > doing something wrong or if I could do it differently to get the seconds to
      > display properly.
      >
      > Const largeInteger As Long = &H1C5EA3B5F585F 1F
      > Const dateRef As Date = #1/1/1601#
      > TextBox1.Text = CStr(DateAdd(Da teInterval.Minu te, CDbl(largeInteg er
      > / (60 * 10000000)), dateRef))
      > 'TextBox1.Text = CStr(DateAdd(Da teInterval.Seco nd, CDbl(largeInteg er
      > / 10000000), dateRef))
      >
      > I am doing this in Visual Web Developer Express.[/color]

      I'd say this counts as a bug. The DateAdd function, despite asking for
      a Double as its second argument, seems to be converting that double to
      an Int32 at some point. Evidence:

      ?dateadd(DateIn terval.Second,2 147000000,now)
      #2/23/2074 3:49:47 AM#
      ?dateadd(DateIn terval.Second,2 148000000,now)
      overflow exception

      Workaround (well, fix): don't use the legacy VB functions; the
      Framework's date handling is better:

      TextBox1.Text = dateRef.AddMinu tes(CDbl(largeI nteger / (60 *
      10000000))).ToS tring
      'or
      TextBox1.Text = dateRef.AddSeco nds(CDbl(largeI nteger /
      10000000)).ToSt ring
      'both work fine

      Even better (in terms of self-documenting code), convert largeInteger
      to a TimeSpan (documenting the conversion factor), then just add it to
      dateref.


      --
      Larry Lard
      Replies to group please

        Comment

        • Rich Raffenetti
          #3
          Re: DateAdd function malfunctions?

          Larry,
          Thanks a load. It works great! I was hoping for a different way like
          this. It's not always clear what is legacy.

          Do you recommend any reference books that describe these nitty-gritty
          details for .Net?
          Rich

          "Larry Lard" <larrylard@hotm ail.com> wrote in message
          news:1139583364 .826212.247200@ g14g2000cwa.goo glegroups.com.. .[color=blue]
          >
          > Rich Raffenetti wrote:[color=green]
          >> I have the following code. If I do the dateadd function with
          >> dateinterval.mi nute, it works fine and the date/time value is displayed
          >> with
          >> zero seconds. If I do the dateadd function with dateinterval.se cond, an
          >> error is thrown saying I have an overflow. I would be happy to know if I
          >> am
          >> doing something wrong or if I could do it differently to get the seconds
          >> to
          >> display properly.
          >>
          >> Const largeInteger As Long = &H1C5EA3B5F585F 1F
          >> Const dateRef As Date = #1/1/1601#
          >> TextBox1.Text = CStr(DateAdd(Da teInterval.Minu te,
          >> CDbl(largeInteg er
          >> / (60 * 10000000)), dateRef))
          >> 'TextBox1.Text = CStr(DateAdd(Da teInterval.Seco nd,
          >> CDbl(largeInteg er
          >> / 10000000), dateRef))
          >>
          >> I am doing this in Visual Web Developer Express.[/color]
          >
          > I'd say this counts as a bug. The DateAdd function, despite asking for
          > a Double as its second argument, seems to be converting that double to
          > an Int32 at some point. Evidence:
          >
          > ?dateadd(DateIn terval.Second,2 147000000,now)
          > #2/23/2074 3:49:47 AM#
          > ?dateadd(DateIn terval.Second,2 148000000,now)
          > overflow exception
          >
          > Workaround (well, fix): don't use the legacy VB functions; the
          > Framework's date handling is better:
          >
          > TextBox1.Text = dateRef.AddMinu tes(CDbl(largeI nteger / (60 *
          > 10000000))).ToS tring
          > 'or
          > TextBox1.Text = dateRef.AddSeco nds(CDbl(largeI nteger /
          > 10000000)).ToSt ring
          > 'both work fine
          >
          > Even better (in terms of self-documenting code), convert largeInteger
          > to a TimeSpan (documenting the conversion factor), then just add it to
          > dateref.
          >
          >
          > --
          > Larry Lard
          > Replies to group please
          >[/color]


            Comment

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